128 TREE WOUNDS AND DISEASES 



struction of the leading shoots of the tree it 

 attacks. It enters by boring a hole into the 

 side of the shoot until it reaches the pith, after 

 which the course is directed upwards, and an 

 exit made at the terminal bud. This tunnel- 

 ling of the shoot so weakens it that frequently 

 during stormy weather it is broken across at 

 the point where the beetle entered. Not only 

 are unhealthy trees attacked by the pine beetle, 

 but young and robust-growing specimens 

 frequently fall a prey to its insidious depreda- 

 tions. June, July, and August are the months 

 when it is most commonly found. The only 

 remedy is collecting and burning the affected 

 shoots work that requires to be done with 

 the utmost care to prevent the escape of the 

 wary insect. Burning all brushwood in planta- 

 tions is a great preventive. 



Wherever Scotch pines are grown the beetle 

 is usually abundant, and at Bostal Wood, in 

 the Metropolitan area, its attacks on these 

 trees have been persistent and severe for many 

 years. 



On the Woburn estate, the writer had to 

 cut down about seventy acres of a Scotch pine 



